Vitamin D Reduces Incidence and Duration of Colds in Those with Low Levels

Reminds me of the old, with treatment, most colds will be cured in just 7 days! Without treatment they generally last about a week.

That said, do not underestimate the health benefits of the placebo effect. It can help a lot. Particularly with anything to do with stress.

So your statement should have been, "it seems to help."

Part of the issue with vitamin supplements is that the bioavailability can be unpredictable. The actual amount absorbed can vary between 10% and 100% depending on the time of day, supplement formulation, what foods if any are taken together, as well as the particular characteristics of the individual's intestines, which are difficult to assess. Because supplements are not regulated as pharmaceuticals in the United States, this variability can be severe; in the worst cases, supplements do not even contain the active principle.

So, I am not surprised that someone needs to take 5000 IU to get 600 IU worth of effect. Institutional medical authorities are (rationally) quite defensive when cautioning readers about supplement consumption; they must consider the worst case (100% bioavailability) when assessing the risk of overdose.

As an alternative to vitamin supplements, exposing common dietary mushrooms to ultraviolet light converts (by an uncatalysed photochemical reaction) the ergosterol therein to calciferol. How best to achieve this in a home setting is unclear.

I experimented with taking 10,000 IU a day for about a year. I had my D levels checked with my normal yearly blood test (lipids, etc) and it put me into the high normal range. I still take 5000 IU daily and have for years with no ill effects.

I should note that I live in a place that sees little sun for five or so months a year.

As has been commented elsewhere, everyone absorbs vitamin D differently, this really is a matter where someone should just get tested, if they (and their doctor) decide supplementation is needed, do so, test again, and adjust dosage accordingly until desired levels are attained.

Not medical advice here, but harmful effects from vitamin D exposure/toxicity generally only happen at very high levels, or if high doses are taken over long periods of time (as excess can be stored in fatty tissue/liver). Doctors often prescribe a very high dose (like 50,000 IUs) for individuals who are very deficient (often taken once a week, not daily) for a short period before going on a more standard (400-2,000, maybe 5,000) IU dose for maintenance.

The advice on this is all over the map and that's a big problem in the space. Reputable medical sources have recommendations almost two orders of magnitude off from each other at times.

This article, for example:

https://www.ccjm.org/content/89/3/154

...cites several cases where daily supplementation of 50K IU was required to restore normal D levels, although also a case where that same dose caused toxicity. As one of the other commenters in the thread noted, working with your doctor to establish the right level is probably the right move. If nothing else, they have the capability to test your serum levels to see where you're at.

One number is not going to work for everyone. The only way to be sure is to get a blood test for Vitamin D levels. I get tested with my yearly physical, but if someone really cares they can get more frequent blood tests.

You can't possibly have the same recommendation for all geographies. Florida and Scotland have somewhat different level of UVB especially throughout the winter, come on.

How much were you taking?

If you dry your mushroom the sun they generate a crap-ton of d2. There was a study earlier this year.

I'm not sure that people downvoting you have been around northerners much. Down here in the upper midwest US, we tend to consider 4 or 5C to be shorts weather in the spring. I've a friend who would wear flip flops / sandals outside down to roughly -10C.

Then again, most people aren't getting the equivalent of 15 minutes of index 7 UVB exposure at those temperatures, so it's not quite the same thing, but still.

Wear a g-string if you want. It doesn't make the sunlight any brighter in winter.

Yes, yes, you're an invincible winter god upon whom the temperature means nothing. Let us all acknowledge that and bow before you.

Now tell me everyone is doing that, all the time. I also live fairly north, which is part of why I've learned this about Vitamin D in my own research, and I can't help but notice that stores selling winter coats and gloves and other assorted cold gear don't go out of business ever year because nobody is buying them. Nor do I walk through a crowd of people in the middle of winter and have people point and laugh at me because I'm the only one in a coat.

Come on. You're just arguing to argue and swagger a bit, not because you actually think people are getting enough sun exposure in the middle of winter to get enough Vitamin D and there's nothing to worry about.

And humans aren't dogs.

Wow, that is interesting. They can synthesise it in their liver?

Sure, many things are vitamins for one species but not another. (In fact, every vitamin must be able to be produced by at least one species – where else would it come from?)

50 IU is nothing. 3000 IU is something. I have MS, so I need to supplement at least 10k IU.

And yeah, it does not absorb well unless you eat some fat.

50IU is a minuscule dose though, no? If people are recommended to supplement, they generally take a dose in the range of a few thousand.

If your doctor is not seeing results they’ll keep upping the dose and I’ve heard of some that sound like an attempt at assisted suicide. Most of us would get toxicity from some of the ones I’ve heard.

I can use myself as an example: I have crohn's disease and I can take doses of 50000UI for some weeks, then 4000UI daily and after a year have my Vitamin D results as low as 20ng/ml.

Echo this with a PSA: it's a simple test to get your levels, and I'm a proponent of ensuring it's included when you have other regular blood tests (may have to ask for it). That can allow a person to see patterns, how effective any supplementation (and different amounts) are, etc.

I tried a 1000 IU vitamin D pills to no avail. Bumped it up to 5000 IU and still saw very marginal bumps in my blood tests

I think I might try daily 10000IU after showing my doctor how little it's moving the needle for me

If eating a "good balanced diet" were easy/normal, we'd have close to zero disease. Supplements are definitely a way to get as close as possible to balance when day to day food intake is chaotic.

Are they that unpopular? Seem like a staple of an English Breakfast.

Vitamin D supplementation in the UK - now there is a fascinating topic.

With the industrial revolution there was a problem of kids in cities getting rickets. This was due to a lack of vitamin C and that was due to a lack of daylight due to the smog.

The solution was to take the kids out of the city so they could spend time in the countryside.

However, along with the industrial revolution came steam trains, and, with steam trains, it became a lot easier to get fresh food from the farm to the city table.

Milk became an early commodity for this railway trade, in the days before refrigeration. Bottling had to be invented too, along with pasteurisation to get the modern milk product. They fortified it with vitamin D and, in time, made it mandatory in schools for kids to have dinky bottles of milk for their morning break. All kids hated the stuff but it was 'good for them' and good for keeping farmers gainfully employed.

Then the clean air acts came along, with the first street to ban fires in fireplaces being opposite the smoke free coal factory, the factory being anything but smoke free. Deindustrialisation happened too, so there were no cities with smokestack industries at their heart.

With clean air there was no longer any need to fortify the milk with vitamin D, so that stopped. From now on, kids would get their vitamin D doing things such as playing in the school playground.

But then we became seriously car dependent and the age of the free-range child was over. With 'stranger danger' and screens (initially just TV) taking over, we entered a new era of people not getting enough daylight again.

Along the way vitamin D has been downgraded, much like Pluto, from being a 'vitamin' to being a hormone. A lot of people want to point this out and explain the science to you. From hearing how some talk about vitamin D, it sounds like the recommended supplements are all over the place.

Clearly there are millions, if not billions that seem to be living just fine with not much sunlight in their lives and on no vitamin D supplements. Where's the rickets? Good question, but then, in Antarctica, where there are months of darkness to endure, they are on something like 20,000 units a day, and they probably know what they are doing.

Maybe following their example for this winter could be my next 'nutrition experiment'. Sometimes, when there is so much conflicting information, it is best to do an n=1 experiment with one's own body.

Minnesota, not Wisconsin. Same latitude and a fair point.

It's only criminal if they aren't provided with the education/information they need to live healthy lives (which is possible with the right diet/supplements).

I'm an Asian who was born and raised in a tropical weather region of my country. I'm now living in the PNW region of the US and it's always miserable from November-April. Vitamin D helps but it's not the same.

It was never about doing right for people, it was about making unbelievable gobs of money using them as pawns.

> which is worse due to cloud cover.

Not just cloud cover. Most areas in the PNW, the sun is so low in the sky between October and March that you can't synthesize vitamin D through the skin at all during those months, even on a bright sunny day.

Even during the summer up here, you really only get a window of roughly 10am to 3pm where enough UV-B rays can penetrate the atmosphere, in July. It's estimated that >80% of the PNW population are deficient (compared with 40% nationwide in the US).

Few words good

Chimney next best invention.

Doors are such an important invention that multiple unrelated animals have evolved modified body parts to serve as doors to burrows¹. Being able to store food is critically important for surviving low-food periods like winter without migrating. "Indoors" lets you store food without insects or other animals getting to it & stealing it. Fire allows for hardening clay, which lets you make a special tiny "indoors" called a "pot" for storing food. Also bricks so "indoors" can be made anywhere. With a roof the rain stays out & you can stay dry & warm, and not freeze at night. A significant portion of why fire is so important is it enables creating various sorts of "indoors".

¹https://en.wikipedia.org/wiki/Phragmosis

Maybe better.

If I have to survive the night, overhead protection and thermal insulation is more important than a fire. Source: I've tried using both without the other.

Privileged comment. Walks in a controlled greenhouse without allergenic pollinators also work, but the poor can't easily access either in the US.